Front engine attachment system for an aircraft engine, having a beam made in three parts

ABSTRACT

A front engine attachment system for an aircraft engine, the front engine attachment system having an engine pylon having, in its front part, a frontal part having an attachment wall with a front face, and a front engine attachment having a beam fastened to the front face and to which a link-rod system is fastened on either side of a median plane. The beam has front, intermediate and rear plates. The rear plate is pressed against the front face. The front plate is disposed in front of the rear plate. The intermediate plate is disposed between the front plate and the rear plate. Each link-rod system is fastened to the intermediate plate in an articulated manner by at least one first connection point and is configured to be fastened to a front part of the engine in an articulated manner by at least one second connection point.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of the French patent application No.1905338 filed on May 21, 2019, the entire disclosures of which areincorporated herein by way of reference.

FIELD OF THE INVENTION

The present invention relates to a front engine attachment system for anaircraft engine, and to an aircraft having at least one such frontengine attachment.

BACKGROUND OF THE INVENTION

An aircraft conventionally has at least one engine, in particular a jetengine. Beneath each wing, and for each engine, the aircraft has anengine pylon that is fastened to the structure of the wing and extendsbelow the wing, and the engine is suspended beneath the engine pylon.

The engine is fastened to the engine pylon via an engine attachmentsystem comprising a front engine attachment and a rear engineattachment.

The front engine attachment has, for example, a beam that is fastened toa front face of the engine pylon and two link rods that are fastenedbetween the beam and a front casing of the engine. Each link rod isequipped with ball joints that are made up of two cut-off and pairedballs.

Each link rod and the beam define, in combination, a primary load pathbetween the engine and the engine pylon, so as to withstand the loads ofthe engine under normal operating conditions of the engine.

Such a beam is a solid component, obtained by machining a componentobtained by forging. The method for obtaining this beam is relativelylong and complex.

Although such a beam is satisfactory from the point of view of its use,it is necessary to find a different architecture so as to make itsmanufacture and implementation easier.

SUMMARY OF THE INVENTION

An object of the present invention is to propose a front engineattachment system of which the beam is in three parts so as to be easierto produce.

To this end, a front engine attachment system for an engine of anaircraft is proposed, the front engine attachment system having:

-   -   an engine pylon having, in its front part, a frontal part having        an attachment wall that has a front face, and    -   a front engine attachment having a beam that is fastened to the        front face and to which a link-rod system is fastened on either        side of a median plane,

wherein the beam is made up of a front plate, an intermediate plate anda rear plate, wherein the rear plate is pressed against the front face,wherein the front plate is disposed in front of the rear plate, andwherein the intermediate plate is disposed between the front plate andthe rear plate, and

wherein each link-rod system is fastened only to the intermediate platein an articulated manner by at least one first connection point and isintended to be fastened to a front part of the engine in an articulatedmanner by at least one second connection point.

Such a front engine attachment system thus has a beam in three parts.Each of these three parts can thus be made from a component that is lessheavy and easier to produce. Moreover, the shape of the link rods isalso simplified.

Advantageously, the fastening of the beam to the front face of theattachment wall is realized by bolts, and each bolt passes through abore in the attachment wall, a bore in the rear plate, a bore in theintermediate plate and a bore in the front plate.

Advantageously, each link-rod system comprises a front link rod and arear link rod, each first connection point between the beam and alink-rod system takes the form of a clevis, one wall of the clevis ismade up of the front link rod of the link-rod system, another wall ofthe clevis is made up of the rear link rod of the link-rod system, theintermediate plate is disposed between the two link rods, and a pinpasses through a bore in each link rod and a bore in the intermediateplate.

Advantageously, the intermediate plate is mounted on the pin via a balljoint connection.

Advantageously, the front engine attachment system has, for eachlink-rod system, a backup safety fastening point that is activated inthe event of failure of a primary load path and creates an auxiliaryload path between the engine and the engine pylon, each backup safetyfastening point is made up of a clevis, the front plate and the rearplate constitute the walls of the clevis, the engine is disposed betweenthe front plate and the rear plate, a pin passes through a bore in thefront plate, a bore in the engine and a bore in the rear plate, and thediameter of the bore in the engine is greater than the diameter of thepin.

The invention also proposes an aircraft having a structure, an engineand a front engine attachment system according to one of the precedingvariants, wherein the engine pylon is fastened to the structure, andwherein a front part of the engine is fastened to the at least onesecond connection point.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned features of the invention, along with others, willbecome more clearly apparent on reading the following description of anexemplary embodiment, the description being given with reference to theappended drawings, in which:

FIG. 1 is a side view of an aircraft according to the invention,

FIG. 2 is a perspective view of a front engine attachment systemaccording to the invention,

FIG. 3 is an exploded perspective view of the front engine attachmentsystem in FIG. 2 , and

FIG. 4 is a cross-sectional view of a ball joint system at a connectionpoint.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description, terms relating to a position areconsidered in relation to an aircraft in a position of forward movement,i.e., as shown in FIG. 1 .

FIG. 1 shows an aircraft 100, which has an engine 102, in particular ajet engine.

In the following description, and by convention, the X direction is thelongitudinal direction of the engine 102, with positive orientation inthe direction of forward movement of the aircraft 100, the Y directionis the transverse direction of the engine 102, which is horizontal whenthe aircraft is on the ground, and the Z direction is the verticaldirection or vertical height when the aircraft is on the ground, thesethree directions X, Y and Z being mutually orthogonal.

In the embodiment of the invention that is shown in FIG. 1 , theaircraft 100 has an engine 102 beneath each wing 103, but it is possibleto provide a plurality of engines beneath each wing 103.

Beneath each wing 103, and for each engine 102, the aircraft 100 has afront engine attachment system 150 that is fastened to the structure ofthe wing 103 and extends beneath the wing 103 and supports the frontpart of the engine 102.

As shown in FIGS. 2 and 3 , the front engine attachment system 150comprises an engine pylon 152, which is fastened to the wing 103, and afront engine attachment 154, which is fastened to the engine pylon 152and to which the front part of the engine 102 is fastened.

In a known manner, the engine pylon 152 takes, for example, the form ofa box that has, inter alia, in its front part, a frontal part 153 thatextends in a substantially vertical plane.

The front engine attachment 154 has a beam 302 to which a link-rodsystem 304 a-b is fastened on either side of a median plane XZ.

In the embodiment of the invention that is presented here, the frontalpart 153 has an attachment wall 158 that has a front face orientedtowards the front of the aircraft 100.

According to the invention, the beam 302 is made up of a front plate 302a, a rear plate 302 b and an intermediate plate 302 c that are fastenedtogether in a removable manner. The front plate 302 a is disposed infront of the rear plate 302 b and the rear plate 302 b is pressedagainst the front face of the attachment wall 158. The intermediateplate 302 c is disposed between the front plate 302 a and the rear plate302 b.

The front plate 302 a, the intermediate plate 302 c and the rear plate302 b each extend in a plane parallel to the front face of theattachment wall 158 and are fastened to the attachment wall 158 by aseries of bolts 602.

The production of the beam 302 from three plates 302 a-c makes it easierto produce the beam 302 since the three plates 302 a-c are effectivelyeasier to produce, in particular since their thickness is smaller thanthe beam of the prior art.

The beam 302 is fastened to the front face of the attachment wall 158,in this case using bolts 602 that pass through a bore in the beam 302and a bore in the attachment wall 158. In the embodiment of theinvention that is presented here, there is a pair of bolts 602 disposedon the port side and a pair of bolts 602 installed on the starboardside, and each bolt 602 passes through a bore in the attachment wall158, a bore in the rear plate 302 b, a bore in the intermediate plate302 c and a bore in the front plate 302 a.

The front engine attachment system 150 also has, in this case, shearpins 604 that pass through a bore in the attachment wall 158, a bore inthe rear plate 302 b, a bore in the intermediate plate 302 c and a borein the front plate 302 a.

Each link-rod system 304 a-b comprises a front link rod 305 a and a rearlink rod 305 b. The two link rods 305 a-b are mutually parallel and thefront link rod 305 a is disposed in front of the rear link rod 305 b inthe longitudinal direction X.

Each link rod 305 a-b is in a plane that is generally parallel to thefront face of the attachment wall 158.

Each link-rod system 304 a-b is fastened to the intermediate plate 302 cin an articulated manner by at least one first connection point 306 a-b,310, and is fastened to a front part of the engine 102, which is shownhere by a part of its front casing, in an articulated manner by at leastone second connection point 308, 312. Each link-rod system 304 a-b isthus fastened only to the intermediate plate 302 c by the at least onefirst connection point 306 a-b, 310.

In the embodiment of the invention that is presented here, the firstlink-rod system 304 a is fastened to the intermediate plate 302 c by twofirst connection points 306 a-b and to the engine 102 by a secondconnection point 308, and the second link-rod system 304 b is fastenedto the intermediate plate 302 c by a first connection point 310 and tothe engine 102 by a second connection point 312.

For each connection point 306 a-b, 310, 308, 312, the connection betweenthe link-rod system 304 a-b and the intermediate plate 302 c, or theengine 102, is realized by a clevis, wherein each link rod 305 a-b ofthe link-rod system 304 a-b constitutes a wall of the clevis and whereinthe intermediate plate 302 c, or the engine 102, is disposed between thetwo link rods 305 a-b, wherein a pin passes through a bore in each linkrod 305 a-b and a bore in the intermediate plate 302 c, or the engine102, and wherein the intermediate plate 302 c, or the engine 102, ismounted on the pin via a ball joint connection.

FIG. 4 shows a ball joint system 400 at the first connection point 310between the link-rod system 304 b and the intermediate plate 302 c. Theother connection points can take the same form, in particular at theengine 102.

The ball joint system 400 comprises a cage 402, which is fastened insidethe bore in the intermediate plate 302 c, for example by screwing, andthe pin 404, which is fitted and fastened in the bore in theintermediate plate 302 c and in the bores in the link rods 305 a-b, inthis case via bushings and a bolt 406 that sandwiches the link rods 305a-b, in this case via washers.

The cage 402 has a spherical inner surface and the pin 404 bears aspherical central boss 408 around which the cage 402 is disposed. Thus,there is freedom of movement between the link rods 305 a-b and theintermediate plate 302 c, the intermediate plate 302 c and the cage 402being able to pivot about the central portion 408.

Such an arrangement allows more robust behavior by protecting thehousing from frictional wear, and ensures easier dismantling if need be.

Thus, in the embodiment of the invention presented here, each firstconnection point 306 a-b, 310 between the beam 302 and a link-rod system304 a-b takes the form of a clevis, wherein one wall of the clevis ismade up of the front link rod 305 a of the link-rod system 304 a-b,wherein the other wall of the clevis is made up of the rear link rod 305b of the link-rod system 304 a-b, wherein the intermediate plate 302 cis disposed between the two link rods 305 a-b, and wherein a pin passesthrough a bore in each link rod 305 a-b and a bore in the intermediateplate 302 c.

In the same way, in the embodiment of the invention presented here, eachsecond connection point 308, 312 between the engine 102 and a link-rodsystem 304 a-b takes the form of a clevis, wherein one wall of theclevis is made up of the front link rod 305 a of the link-rod system 304a-b, wherein the other wall of the clevis is made up of the rear linkrod 305 b of the link-rod system 304 a-b, wherein the engine 102 isdisposed between the two link rods 305 a-b, and wherein a pin passesthrough a bore in each link rod 305 a-b and a bore in the engine 102.

Each link rod system 304 a-b, the intermediate plate 302 c and thefrontal part 153 define, in combination, a primary load path between theengine 102 and the engine pylon 152, so as to withstand the loads of theengine 102 under normal operating conditions of the engine 102.

For increased safety, the front engine attachment system 150 has, foreach link-rod system 304 a-b, an additional connection point 314 a-b.The additional connection points 314 a-b are disposed on either side ofthe median plane XZ, and each establish an additional connection betweenthe front engine attachment system 150 and the engine 102. Eachadditional connection point 314 a-b takes the form of a backup safetyfastening point (or “waiting fail-safe”) that will compensate for afailure of the primary load path, that is to say, of at least one of thelink rods 305 a-b. This means that when a component of the primary loadpath is damaged, the activation of a backup safety fastening pointcreates an auxiliary load path between the engine 102 and the enginepylon 152.

Each backup safety fastening point 314 a-b is made up of a clevis,wherein the front plate 302 a and the rear plate 302 b constitute thewalls of the clevis and wherein the engine 102 is disposed between thefront plate 302 a and the rear plate 302 b, wherein a pin passes througha bore in the front plate 302 a, a bore in the engine 102 and a bore inthe rear plate 302 b, wherein the diameter of the bore in the engine 102is greater than the diameter of the pin. Thus, in normal operation thereis no contact between the pin and the engine 102, and, if one of thelink rods 305 a-b breaks, the engine 102 will move and the pin thencomes into contact with the engine 102.

For each of the clevises described above, the pin of the clevis isgenerally parallel to the longitudinal direction X.

Although not shown in the figures, the rear plate 302 b, front plate 302a and intermediate plate 302 c forming the beam are connected togetherby any appropriate and removable means, such as bolts, in order that thebeam does not come apart when it is detached from the pylon. It is thuseasier for operatives tasked with carrying out maintenance on theaircraft equipped with the front engine attachment system according tothe invention to carry out their work.

While at least one exemplary embodiment of the present invention(s) isdisclosed herein, it should be understood that modifications,substitutions and alternatives may be apparent to one of ordinary skillin the art and can be made without departing from the scope of thisdisclosure. This disclosure is intended to cover any adaptations orvariations of the exemplary embodiment(s). In addition, in thisdisclosure, the terms “comprise” or “comprising” do not exclude otherelements or steps, the terms “a” or “one” do not exclude a pluralnumber, and the term “or” means either or both. Furthermore,characteristics or steps which have been described may also be used incombination with other characteristics or steps and in any order unlessthe disclosure or context suggests otherwise. This disclosure herebyincorporates by reference the complete disclosure of any patent orapplication from which it claims benefit or priority.

The invention claimed is:
 1. A front engine attachment system for an engine of an aircraft, the front engine attachment system having: an engine pylon having, in a front part, a frontal part having an attachment wall that has a front face, and a front engine attachment having a beam that is fastened to the front face and to which a link-rod system is fastened on either side of a median plane, wherein the beam is made up of a front plate, an intermediate plate and a rear plate, wherein the rear plate is pressed against the front face, wherein the front plate is disposed in front of the rear plate, and wherein the intermediate plate is disposed between the front plate and the rear plate, wherein the front and rear plates contact the intermediate plate, and wherein each link-rod system is fastened only to the intermediate plate in an articulated manner by at least one first connection point and is configured to be fastened to a front part of the engine in an articulated manner by at least one second connection point, wherein each link-rod system comprises a front link rod and a rear link rod, wherein the front link rod and the rear link rod being mutually parallel, wherein the front link rod being disposed in front of the rear link rod in a longitudinal direction, wherein the front link rod and the rear link rod residing in a plane that is generally parallel to the front face of the attachment wall, wherein each at least one first connection point between the beam and the link-rod system is formed as a clevis, wherein one wall of said clevis is made up of the front link rod of said link-rod system, wherein another wall of said clevis is made up of the rear link rod of said link-rod system, wherein the intermediate plate is disposed between the front and rear link rods, wherein a pin passes through a bore in each link rod and a bore in the intermediate plate, wherein each link-rod system is fastened to the intermediate plate in an articulated manner by the at least one first connection point and is fastened to the front part of the engine in an articulated manner by at least one second connection point, wherein each link-rod system is fastened only to the intermediate plate by the at least one first connection point, wherein a first link-rod system is fastened to the intermediate plate by a first and a second first connection point and to the engine by one second connection point, wherein a second link-rod system is fastened to the intermediate plate by a third first connection point and to the engine by another second connection point.
 2. The front engine attachment system according to claim 1, wherein the fastening of the beam to the front face of the attachment wall is realized by bolts, and wherein each bolt passes through a bore in the attachment wall, a bore in the rear plate, a bore in the intermediate plate and a bore in the front plate.
 3. The front engine attachment system according to claim 1, wherein the intermediate plate is mounted on the pin via a ball joint connection.
 4. The front engine attachment system according to claim 1, wherein it has, for each link-rod system, a backup safety fastening point that is activated upon a failure of a primary load path and creates an auxiliary load path between the engine and the engine pylon, wherein each backup safety fastening point is made up of a clevis, wherein the front plate and the rear plate constitute walls of the clevis, wherein the engine is disposed between the front plate and the rear plate, wherein a pin passes through a bore in the front plate, a bore in the engine and a bore in the rear plate, and wherein a diameter of the bore in the engine is greater than the diameter of the pin.
 5. An aircraft having a structure, an engine and a front engine attachment system according to claim 1, wherein the engine pylon is fastened to the structure, and wherein the front part of the engine is fastened to said at least one second connection point. 